Treatment efficiency of mini-implant-borne distalization depending on age and second-molar eruption.

OBJECTIVE

The aim of this study was to evaluate the efficiency of molar distalization depending on age and second-molar eruption using the Beneslider.

MATERIALS AND METHODS

Treatment of 51 patients (mean age 17.8 ± 9.6 years) was investigated retrospectively by means of pre- and posttreatment cephalograms. Patients were divided into three groups: 14 children with unerupted upper second molars (group 1), 23 adolescents with second molar in place (group 2), and 14 adults (group 3). The distalization forces applied were 2.4 N in group 1 and 5.0 N in groups 2 and 3. Treatment changes were evaluated and examined statistically for significant differences.

RESULTS

In all patients a Class I molar relationship was achieved. All mini-implants remained stable during treatment. Mean distalization distance as measured by the displacement of the center of resistance was 3.6 ± 1.9 mm (range 1.2-8.5 mm depending on treatment needs). Since no significant tipping was detected, the type of movement can be described as bodily movement. Mean overall distalization speed was 0.6 ± 0.4 mm per month. There were no statistical differences between the groups.

CONCLUSION

We found the Beneslider to be an effective appliance that enables bodily distalization in adequate treatment time. The higher resistance due to erupted second molars can be compensated by the use of higher forces without significantly reducing distalization speed.